These lectures were given at the MITP Summer School 2018: Towards the Next Effective Quantum Field Theory of Nature. They provide a first introduction to effective field theory, illustrating the basic concepts with concrete examples, mostly from QED.
Basic terminology, steps in the construction of an effective theory
Why effective theories?
QED at very low energy: the Euler-Heisenberg Lagrangian
Matching, photon-photon scattering at low energies
Power counting and loop corrections
Standard-Model Effective Theory (extra slides)
Fermi theory for charged-current quark decay
Renormalization and operator mixing, renormalization group (RG)
Resummation by RG evolution: RG improved perturbation theory
Soft Effective Theory: soft photons in electron-electron scattering
Expansion of loop integrals and the method of regions
ITP, University of Bern